1. Field of the Invention
This invention relates to the field of flexible airfoils for aircraft or kites with ESTOL (extreme short take off and landing) characteristics, either manned or UAV (unmanned aerial vehicle) and tethered or untethered which use wing warping for flight control.
2. Description of the Prior Art
The Rogallo wing is a well known flexible wing useful for hang gliding with flight control depending on shifting the weight of the pilot. The shifting of weight is translated to the wing by cables attached between the wing and a frame supporting the pilot.
A kite having a flexible wing stretched between a leading edge spar and a trailing edge spar is taught by Barresi, U.S. Pat. No. 5,213,289. The airfoil is shaped by inflation of cells in the wing. Control lines are attached to the respective ends of the spars and terminate in right and left control handles. The control lines flex the spars through the control lines to execute maneuvers by the kite.
Another flexible wing that is shaped by ram air is taught by Snyder, U.S. Pat. No. 5,160,100. The flexible canopy is propelled by a small engine and pusher propeller mounted on an airframe that carries the pilot. Control lines extend from the inflatable cells to a movable bar connected to the airframe. Flight control is maintained by movement of the bar translated to the wing through the control lines.
Villinger, U.S. Pat. No. 6,293,490, discloses an aircraft or hang glider with a airframe for supporting the pilot and right and left control lines for raising and lowering the trailing edge of the flexible wing. The trailing edge is stiffened by a spar.